The present invention relates to automated call processing, and, more particularly, is directed to capturing alphabetic characters in an automated call processing environment.
Automated call processing has achieved widespread usage. Applications include call routing, voice mail, directory assistance, order processing, information dissemination and so forth.
However, existing telephone based services in which a caller is interacting with a computer do not capture alphabetic character strings with a high degree of accuracy when the strings comprise letters which are selected from an unlimited or very large domain, such as names. Since the set of character strings cannot be defined in advance, the string must be spelled as it is captured.
Automatically capturing alphabetic spelled character strings using only voice input is not feasible presently because letter recognition accuracy is too low with available voice recognition technology. For example, it is difficult to automatically distinguish "B" from "P".
Methods of automatically capturing alphabetic spelled character strings using only dual tone multifrequency (DTMF) input from a twelve-key keypad on a telephone set are cumbersome, as each telephone key does not uniquely map to a single alphabetic character. Consequently, multiple inputs per letter are required for disambiguation, e.g., to indicate "K" press "5" twice or press "5", "2". These methods are also error-prone due to the problem of the user accidentally pressing the wrong key or multiple keys and being unaware of the error, the so-called "fat finger" effect.